基于二维条码PDF417的数字图像水印算法

Image Watermarking Technique Based on 2-D Barcode PDF417

利用二维条码 (PDF41 7)密度高、容量大、可靠性好的特性 ,提出基于二维条码的数字图像水印嵌入方案 .因二维条码采用纠错能力极强、译码可靠性高的RS差错编码技术 ,从而提高了数字水印的鲁棒性 ,亦可通过选择错误修正等级来调整水印质量 .嵌入算法选择在图像的DCT域进行 ,并由随机映射选择水印嵌入点 ,进一步提高了水印信号保密性 .讨论了该算法的抗JPEG压缩和随机噪声能力 ,该算法可抵抗剪切及尺寸变换攻击 ,数字水印信号同时满足透明性和鲁棒性要求 。

A digital image watermarking method based on 2 D Barcode PDF417 for copyright protection is proposed in this paper. This watermarking algorithm possesses the advantages of high density, capacity and reliability features of 2 D barcode (PDF417). High watermark robustness is achieved via a simple forward error correction technique with Reed Solomon codes, which is the main feature of PDF417 codes. Moreover, the quality of the watermark can be adjusted by selecting the error correction level. The embedding region is chosen in the low frequency coefficients in DCT domain, and the watermarking is embedded into the host signal randomly,which improves the security of the watermark. The new technique produces a watermarked image retaining closely the quality of the original host image, surviving concurrently various image processing operations, such as lossy JPEG compression, adding noise, resizing and cutting. The experimental results demonstrate its effectiveness.